Method and system for thermal and compression therapy relative to the prevention of deep vein thrombosis

ABSTRACT

A DVT and temperature therapy system. A temperature therapy blanket includes a fluid bladder for delivering hot and/or cold therapy to a patient. The temperature therapy blanket may also include an air bladder for providing compression. The DVT system functions independently of the temperature therapy. This Abstract is provided to comply with rules requiring an Abstract that allows a searcher or other reader to quickly ascertain subject matter of the technical disclosure. This Abstract is submitted with the understanding that it will not be used to interpret or limit the scope or meaning of the claims. 37 CFR 1.72(b).

CROSS-REFERENCE TO RELATED APPLICATIONS

The present application is a continuation of U.S. patent applicationSer. No. 11/733,709, filed Apr. 10, 2007, now U.S. Pat. No. 9,119,705.U.S. patent application Ser. No. 11/733,709 claims priority from, andincorporates by reference for any purpose the entire disclosure of eachof U.S. Provisional Patent Application Ser. No. 60/791,132 filed Apr.11, 2006 and U.S. Provisional Patent Application Ser. No. 60/817,932filed Jun. 30, 2006. This application hereby incorporates by referencecommonly assigned U.S. Pat. Nos. 5,097,829, 5,989,285, and U.S. PatentApplication Serial Nos. 60/488,709 filed Jul. 18, 2003, 60/550,658 filedMar. 5, 2004, 60/558,453 filed Jul. 16, 2004, Ser. No. 09/328,183 filedJun. 8, 1998, and Ser. No. 10/894,369 filed Jul. 19, 2004. U.S. patentapplication Ser. No. 11/733,709 and U.S. Provisional Patent ApplicationNos. 60/791,132 and 60/817,932 are each incorporated herein byreference.

BACKGROUND OF THE INVENTION

Technical Field

The present invention relates to medical therapy systems in general,including therapeutic cooling, heating, and compression systems used inassociation therewith, and more particularly, but not by way oflimitation, to a programmable, thermal therapy and external pneumaticcompression for the prevention of deep vein thrombosis.

Description of the Related Art

Considerable medical attention has been given to the serious medicalissue of Deep Vein Thrombosis (“DVT”). One approach to the prevention ofDVT has been External Pneumatic Compressions (“EPC”). EPC has been shownto be helpful as a prophylaxis for DVT, although refinements overexisting systems are still in need. For example, multiple articles havebeen written addressing this issue, including a compilation ofrecommendations for preventing DVT (Heit J A: Current Recommendationsfor Prevention of Deep Venous Thrombosis. In: Handbook of VenousDisorders. Gloviczki P, Yao J S, eds. Cambridge, The University Press,1996). Engineering studies are presented which also address EPC as apreventative for DVT (Kamm R D: Bioengineering Studies of PeriodicExternal Compression as Prophylaxis Against Deep Vein Thrombosis—Part 1:Numerical Studies. J Biomech Engineering 104(1): 87-95, 1982). Suchefforts are meritorious for patient health due to possible PulmonaryEmbolism (“PE”) resulting from DVT (National Institutes of HealthConsensus Development Conference Statement: Prevention of VenousThrombosis and Pulmonary Embolism. JAMA 6(2) 744-749, 1986).Additionally, studies have been performed relative to DVT and orthopedicsurgery (“OS”) (Westrich G H, Sculco T P: Prophylaxis Against Deep VeinThrombosis After Total Knee Arthroplasty. J Bone Joint Surg 78-A(6):826-834, 1996).

Relative to OS, physicians have long recognized the need to providewarmth and cooling directly to patients as part of OS therapy. Betterrecoveries have been reported, for example, using cold therapy fororthopedic patients. The benefits of warming patients undergoing surgeryhas also been demonstrated. It may also be desirable to cool portions ofa patient's anatomy in certain circumstances. Yet another advantageoustherapy is the application of heat then cold to certain injured areas.See, for example, U.S. Pat. No. 5,989,285 (the '285 patent) assigned toThermotek, Inc. and incorporated herein by reference.

Several devices have been developed that deliver temperature-controlledfluids through pads or convective thermal blankets to achieve the abovethermal purpose. Typically these devices have a heating or a coolingelement, a source for the fluid, a pump for forcing the fluid throughthe pad or blanket, and a thermal interface between the patient and thetemperature-controlled fluid. U.S. Pat. No. 4,884,304 to Elkins isdirected to a mattress-cover device that contains liquid flow channelsthat provide the selective heating or cooling by conduction.

Devices have also been developed for providing heat to a person in bed.Electric blankets containing electric heating elements have been usedfor years to warm a person in bed. Cooling blankets, such as the blanketdisclosed in U.S. Pat. No. 4,660,388 to Greene, have also been proposed.Greene discloses a cooling cover having an inflatable pad with plenumchambers at opposite ends thereof. Cool air is generated in a separateunit and directed to the pad and out a number of apertures on theunderside of the pad and against the body of the person using the cover.

A disposable heating or cooling blanket that has three layers offlexible sheeting is disclosed in U.S. Pat. No. 5,125,238 to Ragan, etal. Two of the layers form an air chamber and the third includes acomfortable layer for contact with the patient. Conditioned air isdirected toward the covered person through a multiplicity of orifices inthe bottom layers of the blanket.

The temperature-controlled blanket and bedding assembly disclosed in the'285 patent includes a temperature-controlled blanket andtemperature-controlled bedding system that provide both recirculatingtemperature-controlled fluid and temperature-controlled gas to enhanceperformance for convectively heating or cooling a patient. Counter-flowor co-flow heat-exchanging principles between the temperature-controlledliquid and the temperature-controlled gas achieve temperature uniformityacross different sections of the blanket and the bedding system. Drapesand the temperature-controlled bedding system provide atemperature-controlled envelope around a person using the beddingsystem. In one embodiment of the bedding system, an air portion of thebedding system is provided that supplies a fluid portion of the overallbedding system. In another embodiment of the bedding system, the fluidportion of the bedding system is provided for use with a patient bedthat supplies the air portion of the overall bedding system.

U.S. Pat. No. 5,097,829 to Quisenberry describes an improvedtemperature-controlled fluid-circulating system for automaticallycooling a temperature-controlled fluid in a thermal blanket with athermoelectric-cooling device having a cold side and a hot side whenpowered by electricity. The temperature-controlled fluid is cooled by acold side of the cooling device and is pumped through, to, and from theblanket through first and second conduits.

BRIEF SUMMARY OF THE INVENTION

The present invention relates to thermal therapy and DVT compressionsystem for use in heating or cooling a patient. In one aspect of theinvention, a DVT therapy system includes at least a control unitadapted, a thermal-treatment blanket, a compressive-therapy treatmentdevice, a first set of connector tubes, and a second set of connectortubes. The control unit is adapted to heat and cool a heat-transferliquid within about 37-105° F. and to provide compressed air at apressure of at least 25 mmHg above ambient atmospheric pressure. Thethermal-treatment blanket is adapted for receipt of the transfer liquidfrom the control unit and to send the heat-transfer liquid back to thecontrol unit, a compressive-therapy treatment device adapted to utilizethe compressed air from the control unit, and a first and second set ofconnector tubes. The first set of connector tubes is adapted tofacilitate the flow of the heat-transfer liquid between the control unitand the thermal treatment blanket. The second set of connector tubes isadapted to facilitate the flow of the compressed air between the controlunit and the compressive treatment device.

In another aspect, a DVT method includes providing a control unitadapted to heat and cool a heat-transfer liquid to a temperature withinthe range of about 37-105° F. and adapted to provide compressed air at apressure of at least 25 mmHg above ambient atmospheric pressure,providing a thermal treatment blanket adapted for receipt of theheat-transfer liquid from the control unit and for sending theheat-transfer liquid back to the control unit, and applying a hot orcold treatment to an individual's skin area. The method also includesproviding a compressive-therapy treatment device utilizing thecompressed air from the control unit and applying a compressivetreatment to an individual's skin area. The method further includesproviding a first set of connector tubes adapted to connect the controlunit and the thermal treatment blanket to facilitate the flow of theheat-transfer liquid therebetween, and providing a second set ofconnector tubes adapted to connect the control unit and the compressivetreatment device to facilitate the flow of the compressed airtherebetween.

In a further aspect of the invention, a DVT therapy treatment deviceincludes an upper and lower sheet of biocompatible material, a firstair-tight, inflatable portion, a second air-tight inflatable portion, afirst hook-and-loop fastener, a second-hook-and-loop fastener, and aninlet. The upper and lower sheet sheets have substantially the sameshape and are sealed on an outer edge thereof. The first air-tightinflatable portion includes an elongated strap formed from both theupper and lower sheets, with the elongated strap being adapted to wraparound an individual's ankle. The second air-tight inflatable portion isattached to the first portion, has two longer sides that are relativelypinched at a location generally in the middle of the longer sides andtwo shorter sides, and is formed from the upper and lower sheets. Thefirst hook-and-loop fastener is on a distal end on the first portion ata location away from the second portion. The second hook-and-loopfastener is disposed on a left edge of the second portion and is adaptedto mate with the first hook-and-loop fastener to secure the DVT therapydevice to the individual's foot for subsequent compressive therapy.

In yet another aspect of the invention, a DVT therapy device includes afirst and second sheet of biocompatible material of a generallytrapezoidal shape having concentric arcuate top and bottom edges, thefirst and second sheet being sealed on an outer edge thereof to createan air-tight inflatable structure, a first and second weld locatedsymmetrically about the center of the first and second sheet, a thirdand fourth weld extending from the first and second welds respectivelyto create an ‘S’ shaped portion disposed in the center of the first andsecond welds, and an inlet for receipt of compressed air from thecontrol unit, the inlet allowing the compressed air to inflate the ‘S’shaped portion to facilitate compressive treatment of the individual'scalf.

BRIEF DESCRIPTION OF THE DRAWINGS

A more complete understanding of the method and apparatus of the presentinvention may be obtained by reference to the following DetailedDescription when taken in conjunction with the accompanying Drawingswherein:

FIG. 1 is a perspective view of a thermal and compression-control systemfor thermal and compression therapy relative to the prevention of DVT;

FIG. 2 is a cut-away, perspective view of the system of FIG. 1illustrating various elements thereof;

FIG. 3 is a cut-away, perspective view of the system of FIG. 1 takenfrom the opposite side of that in FIG. 2;

FIG. 4 is a rearwardly oriented, perspective view of the system of FIG.1;

FIG. 5 is a diagrammatic schematic of the system of FIG. 1, illustratingintegration of thermal and compression elements therewith;

FIG. 6 is a flow diagram illustrating a thermal therapy and DVTcompression process;

FIGS. 7-10 illustrate various embodiments of the present invention;

FIGS. 11A-11G illustrate a DVT foot wrap;

FIG. 12 is a schematic illustrating utilization of one embodiment of thecontrol unit with a more detailed illustration of a thermal therapyblanket;

FIG. 13A is a flow diagram of one aspect of the thermal operation of thethermal therapy system as represented in FIG. 12;

FIG. 13B is a rear view of an integrated reservoir and heat transferassembly (HTA);

FIG. 13C is a perspective view of an integrated reservoir and HTAaccording to a preferred embodiment of the present invention;

FIG. 14 is a plan view of an embodiment of a thermal therapy blanket;

FIG. 15 is a cross-sectional view of the blanket of FIG. 14 illustratingflow of thermal fluid therein and utilization of compression airthereabove for use in achieving a compression of the thermal fluidagainst the skin of a patient;

FIG. 16 is a thermal therapy/DVT system block diagram;

FIG. 17 is a DVT therapy block diagram further illustrating theoperation thereof;

FIGS. 18A-18D illustrate a DVT calf wrap; and

FIG. 19 is a plan view of an embodiment of a thermal therapy blanket.

DETAILED DESCRIPTION OF ILLUSTRATIVE EMBODIMENTS OF THE INVENTION

Applicants have discovered that the use of both thermal therapy andcompression therapy during and for post-surgical treatment for theprevention of DVT is advantageous. As referenced above, numerousarticles have been written on the problems associated with DVT and theutilization of thermal therapy is already well known. Consistenttherewith, methods of and apparatuses for providing pressurized andthermally controlled fluids for use with patients in need of suchtherapy are disclosed. A versatile control unit is adapted for providingone of a plurality of treatment modalities. As described below, in onemodality, a thermally controlled liquid is produced and provided in aconfiguration facilitating flow through a treatment pad or blanket forthermal therapy. In a second embodiment, air compression is providedsuch that a blanket can receive a flow of pressurized air to cause adegree of compression relative to the patient. In a third embodiment,DVT system modules are provided so that the prevention of DVT can beafforded. In a fourth embodiment, thermal therapy is provided with DVTtreatment.

As further described below, a control unit will be shown to be providedwith (a) thermally controlled fluid, (b) thermally controlled fluid andcompression air, and (c) thermally controlled fluid, compression air,and DVT systems. The control unit for providing these selective featuresis described within a single chassis design capable of providing any ofthe modalities therein or herein described. This selective versatilityprovides financial and manufacturing incentives in that the simpledesign selectively can provide an industrial, medical, or electro-opticversion that produces only thermally controlled liquid, such asco-liquid for cooling industrial equipment, in a configuration adaptablefor other applications. Therefore, in one embodiment of the invention,the production of a control unit adapted only for chilling electroniccomponents is conceivable while the same chassis and initial componentsplace therein may also be adaptable for a version that provides aprophylaxis for DVT.

Referring first to FIG. 1, there is shown a thermal andcompression-control unit 4 for thermal and compression therapy. Thecontrol unit 4 is coupled to thermal and compression elements applied toa patient as described below. In this particular view, the control unit4 is shown in perspective to illustrate the assembly of one embodimentof a control unit for pumping air and liquid through tubes to bedescribed below for a patient to be treated therewith.

Referring still to FIG. 1, a lower dark portion thereof includes afilter that is removable from around a grate as illustrated below. Inone embodiment, the filter provides an air-filtering substance such aswoven netting that is attached by VELCRO fasteners or the like outwardlyof a perforated metal grate to allow for the low pressure drawing of airtherethrough to allow cooling of components placed inwardly thereinprior to the upward draw of the air through fans disposed thereabove andthe forcing of said air upwardly across a heat transfer assembly (HTA)202 as presented in FIG. 2.

Referring now to FIG. 2 specifically, the HTA 202 is shown disposedbeneath a fluid reservoir 200. The reservoir 200 is adapted for storageof liquid that may be pumped outwardly through a fluid connectordisposed rearwardly of the reservoir 200. Fluid connector 200A isadapted for connecting to the patient pads or blankets as describedbelow.

Still referring to FIG. 2, there is shown the internal portion of thecontrol unit 4 referenced above illustrating one embodiment of theassembly therein. Within the assembly of the unit 4, a pair of fans 71and 73 are shown disposed above a grate 75. Grate 75 containstherearound the filter portion 77 that may be secured thereto by hookand loop (e.g., VELCRO). The lower portion of the grate is connected toa bottom portion 79 of a chassis 81 in a manner to provide support forelectronic components 83 mounted thereon for providing the adequatepower supply to and control of the HTA 202 and other elements within thecontrol unit 4.

Referring specifically now to a dual-fan arrangement, fans arepositioned to suck air from around the filtered grated region disposedperipherally about the electronic components so that the air flow isboth quiet and at a rate allowing initial electronic cooling and thenbeing available to be pushed into the top section of the control unit 4where most heat dissipation is needed. In essence, the control unit 4facilitates pulling air through the lower power supply that could thenbe forced upwardly for maximum cooling where maximum thermal change isneeded.

Referring still to FIG. 2, an air pump 85 is disposed in a lower portionof a chassis 81 and beneath an air switch 87 disposed beneath a heatsink 89 disposed adjacent to a fluid pump 91. The fluid pump 91 isdisposed in position for collecting fluid from a reservoir 200 that hasbeen thermally controlled by the HTA 202 for passage through the fluidconnector 200A. Thermal electric chips (TEC chips) 93 are shown disposedbetween the heat sink 89 and a thermal transfer plate 95 in a manner toprovide the requisite thermal control of the fluid within the reservoir200. An air connector 97 is shown disposed adjacent to the fluidconnector 200A to provide the requisite dissipation of air from the airpump 85 for use in conjunction with the blanket 8 for application ofpressure in a bladder forcing the thermal fluid flowing from the fluidconnector 200A to be in close contact with the patient as describedbelow.

Referring now to FIG. 3, there is shown a cutaway perspective view ofthe control unit 4 taken from the opposite side thereof and illustratingvarious other aspects therein. Relative to this particular view of thecontrol unit 4, a 500-watt power supply is shown disposed along with a65-watt power supply relative to the chassis 81. The various powersupplies are further defined herein and provide the requisiteperformance necessary for both flexibility and reliability. Inconjunction with the DVT therapy operation, a DVT air pump 119 is showndisposed adjacent to a pair of DVT solenoids 121 mounted on a DVT airbracket 123 adjacent a DVT air switch 125. A pair of solenoids 127 arelikewise disposed relative thereto.

Referring now to FIG. 4, there is shown a rearward-oriented perspectiveview of the control unit 4 illustrating the connectors and couplings onthe rear panel of the control unit 4 as provided for the functionalitydescribed herein. In this particular view, it may be seen that a singleair connector is provided for pressurization of the blankets asdescribed below. Likewise, a pair of fluid connectors are provided inthat the fluid flow requires an outward bound and an inward bound flowof fluid to the fluid reservoir for thermal control. Likewise, the DVTconnectors are provided in a pair, although a single DVT connector isused for each DVT pad. The DVT pads are pressurized in accordance withthe medical modality described herein and the parameters are set by theprogramming within the control boards of the control unit 4. Also shownin the figure is an RS232 connector for data communication with thecontrol unit 4. Other connections are contemplated by the Applicantssuch as, for example, a USB connection or a wireless connection.

Referring now to FIG. 5, there is shown a thermal compression-controlsystem for thermal compression therapy wherein the control unit 4 iscoupled to a thermal blanket 8 by connector tubes 6 coupled to thecontrol unit 4 through a connector 10. The DVT prevention aspect isprovided through a cuff system 31 comprising cuffs 33 and 35 that allowplacement on the feet or other select regions of a patient for the DVTtreatment thereof. The cuffs 33 and 35 are coupled to the control unit 4through connector tubes 37.

Relative to the DVT pulsing, various embodiments of the presentinvention provide for a broad pulse configuration. It has been reportedthat a narrow pulse generated by opening a solenoid on compressed airmay be hazardous due to the intensity of the pulse damaging cells. Abroader pulse as described herein will apparently not cause the samedegree of harm and may reduce harm while maintaining the same degree ofefficiency in the DVT prevention. The other solenoids shown hereinpermit choosing between the right or left routing of the compressionstroke as further defined in other figures.

Referring back to FIG. 5, it may be seen that the connector tubes 37 aremounted to the DVT connectors shown on the rear panel of the controlunit 4 wherein each may provide a pressurized air in accordance with apre-programmed application that maximizes the effectiveness of the DVTprophylaxis. In accordance with principles of the present invention, oneactivation technique is a high pressure low ramp-up sequence wherein theselect pressure for DVT prevention is provided without a high pulserate. It has been found by the Applicants that a high pulse rate timehas been reported to create in part cell damage and it is advantageousin such a DVT prevention system to modify the conventional pulse rate toreduce cell damage. In this manner, the control boards of the controlunit 4 provide a select pressurization in utilization with the solenoidsshown mounted within the DVT system to carefully control the pulse ramptime in accordance with maximum medical treatment of the patientpursuant to medical concerns for such treatment.

TABLE 1 Deflation Pressure, Pressure, Inflation Hold Cycle ApplicationSource Mode mmHg mmHG Time, s Time, s Time, s Comments Calf LiteratureBoth 30-80 0   3-20 1-5 30-80 Predominantly alternating with somesimultaneous Existing Alternating ~45 0 Inc. 12 60 Calf and Foot ProductThermoTek Alternating 45 15 8 1-5 Additional solenoid, line, and Colderconnector Foot Literature Alternating  45-180 0 0.3-5 1-5 20-60Predominantly higher pressures; 3 sec “std” Existing Alternating 120-1800   0.3 1-5 20-60 Product ThermoTek Alternating 120 15 9 2-5 30Additional air pump, line, and fitting

Table 1 illustrates information regarding an embodiment of the inventionrelative to various existing products on the market for addressing calfand foot DVT concerns. All pressure references in Table 1 pertain tommHg above the ambient atmospheric pressure. It will be seen from Table1 that currently available literature indicates an inflation time of3-20 seconds for a calf and around 0.3 seconds for a foot. Suchinflation times are different than those typically used by theApplicants and Applicants' assignee “ThermoTek” as referenced in Table 1wherein the inflation time for one embodiment of the system of thepresent invention is on the order of 8 seconds for a calf in analternating mode. Likewise, relative to the foot, which is oftenspecifically of concern, an inflation time on the order of 9 seconds ascompared to existing literature and existing information regarding acommercially available product in the range of 0.3 seconds. Thisdifferential is, as referenced above, a much more gradual pulse rate andis currently understood by Applicants to create less cell damage for DVTtreatment. The information presented above includes preferred rangeswhile other times are contemplated by the Applicants to be capable ofachieving the desired results.

Referring now to FIG. 6, there is shown a flow diagram illustrating oneembodiment of the present invention wherein the patient is initiallyconnected to the system of control unit 4 in step 831. Next, the controlunit 4 is activated for thermal therapy in step 833 and activated forDVT compression in step 835. The condition of the patient is monitoredin step 837 and the control parameters are adjusted in step 839 forfurther monitoring of the patient. Adjustments in step 839 followmonitoring the patient in step 837 as long as the system is inoperation.

Referring now to FIGS. 7-10 together, each shows an application of anembodiment of the present invention. In FIG. 7, an industrial example isillustrated wherein a cooling umbilical is provided from control unit 4,which cooling umbilical may be utilized to cool electronic equipment astherein illustrated. Likewise in FIG. 8, the control unit 4 is shown tobe connected with three tubes to provide a cooling umbilical for anindividual having thermal therapy therewith. The cooling umbilical isalso connected with an air line that allows an inflation of theparticular wrap shown around the user's knee in this particular view forpurposes of applying pressure thereagainst. This particular thermaltherapy wrap or blanket will be illustrated in more detail below.

Referring now to FIG. 9, there is shown utilization of the control unit4, wherein a cooling umbilical is utilized without any compression andDVT compression is provided for both feet or calves of a patient toillustrate DVT and thermal therapy usage. In FIG. 10, only DVT is beingutilized from the control unit 4 as no thermal therapy umbilicals aretherein utilized.

Referring now to FIG. 11A, there is shown a DVT flat foot blanket layout1100 of the type that may be used in accordance with the principles ofthe present invention. Because of the generic shape of the flat footblanket layout 1100, a foot wrap based on the layout 1100 may be used oneither a left or right foot. It may be understood that a variety ofblanket layouts may be utilized for the foot during DVT treatment. It isthought that these illustrations as depicted in FIGS. 7-11 will furtherfacilitate an understanding of principles of the present invention andenable one skilled in the art to practice same in conjunction with thecontrol unit 4 as described herein.

Referring now to FIGS. 11B-11C, there is shown a contoured foot wrap1104. The foot wrap 1104 is formed from a first sheet of biocompatiblematerial 1102 and a second sheet of biocompatible material 1116 that aresealed together at sealed edge 1110. The first sheet of biocompatiblematerial 1102 and the second sheet of biocompatible material 1116include the front and back of the foot wrap 1104, respectively. The footwrap 1104 includes an upper air-tight inflatable portion 1106 and alower air-tight inflatable portion 1108. The lower air-tight inflatableportion 1108 also includes flaps 1114 and 1116. In various embodiments,flap 1114 and the upper air-tight inflatable portion 1106 include ahook-and-loop fastener hook sealed or sewn onto their front sides andthe back 1116 is Velcro® compatible to receive the hooks. An inlet 1116is located on the back of the foot wrap 1116 on the lower air-tightinflatable portion 1108 to facilitate the intake and exhaust of air.

Referring now to FIGS. 11D-11G, the operation of the foot wrap 1104 isdescribed. With reference to FIG. 11D-11E, a foot is placed into thefoot wrap 1104 with the foot engaging the front side 1102 of the footwrap 1104. With reference to FIGS. 11E-11F, the flaps are pulled tightand the foot wrap 1104 is secured. The contoured foot wrap 1104 may benow be connected to the control unit 4 via a DVT connector 37 connectedto inlet 1116 for DVT therapy according to the present invention, asdepicted in FIG. 11G.

Referring now to FIGS. 18A-18B, there is shown a trapezoidal DVT calfblanket 1802 of the type that may be used in accordance with principlesof the present invention. As with the flat foot blanket layout, avariety of blanket layouts may be used for the calf during DVTtreatment. A calf wrap 1802 is formed of two sheets of biocompatiblematerial 1800 and 1820, including the front and back of the calf wrap1802, respectively. The front 1800 and back 1820 are sealed or sewntogether at a sealed edge 1810. Additionally, the calf wrap is dividedinto three chambers (1804, 1806, and 1808) by welds 1812 and 1814. Themiddle chamber 1806 is characterized by two additional welds 1816 and1818. Weld 1816 extends from weld 1812 and weld 1818 extends from weld1814, creating an ‘S’ shaped chamber. The three-chamber structure asdescribed herein permits a compression gradient across the threechambers. In various embodiments, all welding may be accomplished byradio frequency (RF) welding. The front side 1800 also includes flaps1824 and 1810. In various embodiments, flap 1824 may have sealed or sewnthereon a Velcro® hook and back side 1820 may be Velcro® compatible toreceive the hook. An inlet 1822 is located on the back of the calf wrap1802 to facilitate the intake and exhaust of air.

Referring now to FIGS. 18C-18D, operation of the calf wrap 1802 isdescribed. With reference to FIG. 18C, the calf wrap 1802 is positionedon the front side of the calf. Flap 1826 is pulled tight and then flap1824 is pulled tight overtop and attached. With reference to FIG. 18D,the calf wrap may be connected to the control unit 4 for DVT therapyaccording to the present invention by connecting DVT connector 37 toinlet 1822.

Referring now to FIG. 12, there is shown a thermal therapy applicationwithout pressure applied (similar to the thermal therapy illustrated inFIG. 9). As shown herein, heat transfer fluid flows into the blanket 8through an inlet port, and exits through an outlet port to the controlunit 4 via the connector 10 and connector tubes 6. Gas may be pumped bythe control unit 4 to the blanket 8 through the connector tubes 6 andthe connector 10 to provide compression (not shown in this view). Whilethe embodiment described above pumps gas to provide compression, it isalso contemplated that other substances could be utilized to provide thedesired compression.

The control unit 4 and the blanket 8 may be adapted for theadministration of hot, cold, and/or compression therapies to a bodyportion of the patient. For example, the blanket 8 may cover differentareas of the human body. Current thermal design requirements fortemperature therapy in various embodiments of the present invention areas follows: 1) the system must be able to heat the fluid from around 49°F. to around 105° F. with the largest blanket attached to a typical man(e.g., 5′10″ and 180 lbs.) at an ambient of 77° F. within 10 minutes; 2)the system must be able to cool the fluid from 105° F. to 49° F. withthe largest blanket attached to the typical man at an ambient of 77° F.within 20 minutes; and 3) the system must cool the fluid to 37° F. at anambient of 77° F. within 90 minutes. These requirements should be with aminimum compression of 25 mm Hg. The connector 10 provides a fluidand/or gas connection between the control unit 4 and the blanket 8 forthe transfer of gas and heat transfer fluid. The connector 10 may alsoallow for transfer of electrical sensor signals and/or data signalsbetween the blanket 8 and the control unit 4. The emergency relief valve9 is utilized to quickly decompress the blanket 8 if needed.

Referring now to FIG. 13A, a block diagram of one embodiment of the flowof heat transfer fluid between the control unit 4 and the blanket 8 isillustrated. The control unit 4 includes a heat transfer fluid reservoir200 and at least one heat transfer assembly (HTA) 202 for heating and/orcooling the heat transfer fluid. Before the blanket 8 is utilized fortemperature therapy, the system is primed with the heat transfer fluid.When the system is primed, substantially no air exists in the tubes 204between the reservoir 200, HTA 202, and blanket 8. The flow tubes in thecontrol unit 4 between the reservoir 200, HTA 202, and blanket 8 form athree-point junction 204C. In embodiment, the three-point junction 204Cis formed as an inverted Y, however, other shapes and orientations arepossible. By utilizing a three-point junction 204C, the heat transferfluid returning from the blanket 8 is recirculated to the HTA 202without utilizing heat transfer fluid from the reservoir 200. Thethree-point junction 204C allows the HTA 202 to heat or cool the heattransfer fluid that has already been heated or cooled prior to enteringthe blanket 8. In the preferred embodiment, the HTA 202 does not heat orcool the entire contents of the reservoir 200, but merely the portion ofthe heat transfer fluid that is currently circulating through theblanket 8 and tubing 204. The reservoir is typically by-passed unlessmore fluid volume is needed. In the three-point junction 204C, heattransfer fluid returning from the blanket 8 may be pulled, via a pump,to the HTA 202. If more heat transfer fluid than that which is alreadycirculating through the system is required, then the heat transfer fluidfrom the reservoir is introduced into the system.

Referring now to FIGS. 13B-13C, the integration of the reservoir 200 andthe HTA 202 is illustrated. With reference to FIG. 13B, the rear of thereservoir 200 includes a coolant supply port 1302 for supplying heattransfer fluid to the fluid pump 91, a coolant return port 1304 forreceiving heat transfer fluid from the blanket 8, and a cold plate 1306.The cold plate 1306 is positioned at the base of the reservoir 200 andis therefore in direct contact on its underside with the TEC 93.Referring now specifically to FIG. 13C, a divider 1308 is located in themiddle of the reservoir 200 between the coolant supply port 1302 and thecoolant return port 1304, thereby blocking direct flow of fluid betweenthe two ports. As fluid flows into the back of the reservoir 200 throughthe coolant return port 1304, the divider 1308 channels the fluid to thefront of the reservoir 200 and then back to the coolant supply port1302. By preventing fluid from short circuiting directly from thecoolant return port 1304 to the coolant supply port 1302, the divider1308 forces exposure of the fluid to the cold plate 1306 which, as aresult of its direct contact with the TEC 93, provides a surface area tocool or heat the fluid. The reservoir 200 also includes vertical fins1310 to further enhance contact areas with the fluid. In one preferredembodiment, the vertical fins are spaced 0.5 inches apart and span thelength of the reservoir 200.

Referring now to FIG. 14, a temperature therapy blanket 8 having apre-selected shape and compression capabilities is illustrated. Theunderside of the blanket 8 (shown) is placed directly against a portionof the patient. The fluid bladder is thus adjacent to the patient. Heattransfer fluid flows into the blanket 8 from inlet hose 500 and heattransfer fluid flows out of the blanket via outlet hose 502. A gas forcompression flows into the blanket 8 from air inlet hose 504. Heattransfer fluid travels through the inlet hose 500, through fluid inletport 506, and into the blanket 8. The connections 15 allow the heattransfer fluid to more evenly disperse throughout the fluid bladder.Partitions 508 a, 508 b control the flow of heat transfer fluidthroughout the fluid bladder. Partition 508 a prevents heat transferfluid from entering the blanket 8 at the inlet port 506 and immediatelyexiting the blanket via outlet port 510. Partition 508 a forces the heattransfer fluid to travel towards the end of the blanket 8 remote fromthe inlet port 506. Partition 508 b, in conjunction with connections 15,causes the heat transfer fluid to travel across the width of the blanket8. The edges of the fluid bladder are joined to the edges of the airbladder at seal 512. The heat transfer fluid may then exit the blanket 8at the outlet port 510. The travel of the heat transfer fluid isindicated by arrows.

Referring now to FIG. 15, the blanket 8 is turned over relative to FIG.14 and a cross-sectional view along line A-A of FIG. 14 is illustrated.As described above, the fluid bladder 514 (disposed against the patient)and the air bladder 516 are joined together at seal 512. Connections 15join the upper layer and lower layer of the fluid bladder 514 together.The partition 508 a segregates the heat transfer fluid from the inletport 506, illustrated by downward arrows, from the heat transfer fluidflowing to the outlet port, illustrated by the upward arrows. The airbladder 516 is oriented over the fluid bladder 514 and serves to pressthe fluid bladder 514 against a portion of the patient (not shown inthis view). In another embodiment, the fluid bladder 514 and the airbladder 516 may have low-profile inline ports such as inline ports1902(a)-(c) of a temperature therapy blanket 1900 of FIG. 19. Inlineports afford increased comfort to a user by allowing the blanket 8 tolay substantially flat. The embodiment shown allows users to sleep orrest while using the blanket 8.

Referring now to FIG. 16, there is shown a thermal therapy/DVT systemblock diagram where air is provided in a compression subsystem inconjunction with Peltier cooling of a fluid for thermal therapy. Thecoolant flow is thermally conditioned by the Peltier cooling engine.Patient supply cooling temperature sensors are utilized in conjunctiontherewith. Coolant pumps are utilized in conjunction with cooling fans.The cooling fans, as described above, provide selective cooling in amanner most efficient for the construction and operation of the controlunit 4. In that regard, FIG. 16 may be utilized in understanding variousaspects of operation of the system of the present invention as furtherdefined below.

Various of the above-described Figures illustrate the mounting ofdual-fan assemblies for impinging style airflow. In this manner, the airis brought in at the base of the heat sink and driven in or impingedagainst the heat sink, which serves to lower the pressure drop andincrease air flow for a given heat sink. A single heat sink may be used.Such a configuration of air flow with an enlarged grate configurationmay be used to afford noise abatement.

In one embodiment, the size of the reservoir has been reduced relativeto a number of earlier models of thermo-electric (TEC) systems such thatonly around 175 watts are utilized compared to 205 for typical earliersystems. As such, the control unit 4 is configurable with TEC assembliesmaximizing efficiency. With such an assembly, multiple applications ofindustrial with non-air compression and/or medical with air compressionand/or DVT is afforded in a single chassis 81. With regard to themedical modality, thermal therapy may be afforded to a patient to reduceswelling and edema while, in conjunction with the DVT prophylaxis,preventing blood from pooling in lower body extremities. This isparticularly important after surgery when anesthesia has been involved.It is well known that anesthetics often tend to reduce the wall strengthof veins and, if not otherwise treated, appropriate venous pumping maynot be afforded allowing for blood pooling in clots. With the DVTapplication as disclosed herein, both thermal and DVT prophylaxis with alow-noise configuration may be achieved.

Still referring to FIG. 16, the Peltier power supply is shown to becontrolled by a pt-7c controller accessed via a keypad display. Variousother features for control and power supply have likewise been included,such as an electro-magnetic interference (EMI) filter and auxiliarypower supply used in conjunction with the DVT therapy subsystem. It maybe seen that the DVT therapy subsystem provides a separate airflow forboth left and right applications that were described above forutilization in the DVT treatment of a patient illustrated in FIGS. 9 and10.

For purposes of this patent application, the following definitions areto be used:

-   -   hot: >15° C. greater than ambient temperature;    -   cold: <15° C. less than ambient temperature;    -   about: not more than 10% more or less than stated value;    -   around: not more than 10% more or less than stated value; and    -   biocompatible: referring to a material that the body generally        accepts without a significant immune response.

Referring now to FIG. 17, there is shown a DVT therapy block diagramwhere the air pump is shown to be in flow communication with a compressvalve utilized with a vent valve and a pressure sensor in associationwith a pressure switch high and pressure switch low. This DVT therapyblock diagram is provided to further facilitate an understanding of theDVT therapy provided by the control unit 4 in accordance with variousembodiments of the present invention when DVT compression is providedfrom two outlets of the control unit 4. The various modes of operationutilizing air pump, compression valve, select valve, DVT valve, and ventvalve are shown.

The previous description is of embodiments of the invention. The scopeof the invention should not necessarily be limited by this description.The scope of the present invention is instead defined by the followingclaims.

What is claimed is:
 1. A combination thermal compression method for deepvein thrombosis therapy, the method comprising: thermally conditioning,via a control unit, a fluid to a predetermined temperature; providingthe fluid to a thermal blanket via a hose; returning the fluid to thecontrol unit via the hose; securing the thermal blanket to an extremityof a patient, wherein the thermal blanket is integrated with a firstcompression device and the first compression device is disposedoutwardly of the thermal blanket; securing a second compression deviceto the extremity of the patient at a location distal to the thermalblanket; providing, via a compression subsystem in the control unit,compressed gas to the first compression device to compress the thermalblanket against the extremity so as to deliver a first treatmentmodality to the extremity; applying, via a DVT therapy subsystem in thecontrol unit, pulsed compression therapy treatment to at least theextremity via the second compression device so as to deliver a secondtreatment modality to the patient; and wherein the control unitautomatically directs compressed air alternately to the firstcompression device and the second compression device such that the firsttreatment modality and the second treatment modality are delivered tothe extremity in an alternating fashion.
 2. The method of claim 1,wherein compressed gas is directed first to the first compression devicebefore being directed to the second compression device.
 3. The method ofclaim 1, wherein the compressed gas is directed first to the secondcompression device before being directed to the first compressiondevice.
 4. The method of claim 1, wherein the conditioning comprisesheating the fluid from a pre-determined cold temperature to apre-determined hot temperature and maintaining the pre-determined hottemperature for a set period of time.
 5. The method of claim 1, whereinthe conditioning comprises cooling the fluid from a predetermined hottemperature to a pre-determined cold temperature and maintaining thepre-determined cold temperature for a pre-determined period of time. 6.The method of claim 1, wherein the conditioning comprises alternatinglyheating and cooling the fluid between pre-determined temperatures forpre-determined times.
 7. The method of claim 1, wherein the providingcompressed gas and the applying pulsed compression comprises generatingpressures within the first compression device and the second compressiondevice in the range of approximately 0 to approximately 120 mmHg.
 8. Themethod of claim 1, wherein the control unit comprises a first outletthat facilitates connection of the control unit to the first compressiondevice and a second outlet that facilitates connection of the controlunit to the second compression device.
 9. The method of claim 1, whereinthe thermal blanket may be secured to a variety of anatomical regions ofthe patient.
 10. The method of claim 1, wherein the providing fluid tothe thermal blanket occurs simultaneously with the providing compressedgas to the first compression device.
 11. The method of claim 1,comprising at least two second compression devices; and wherein pulsedcompression therapy is applied to the at least two second compressiondevices in sequence.
 12. The method of claim 1, comprising at least twosecond compression devices; and wherein pulsed compression therapy isapplied to the at least two second compression devices simultaneously.